TRAVERSE CITY,
Mich. (AP) — Oceangoing cargo ships will be required to zap their ballast
water with ultraviolet light, chemicals or other treatments before dumping
it in U.S. waters under a regulation the Coast Guard announced Friday to
prevent species invasions that damage the environment and cause billions in
economic losses.

The long-awaited
rule comes more than two decades after environmental groups began pushing
for a crackdown on ballast water, which provides stability in rough seas but
often harbors stowaway species from abroad. When the soupy mixtures of water
and sediment are discharged in U.S. ports, the newcomers can spread rapidly,
starve out native competitors and spread diseases.

Zebra and quagga
mussels that hitched a ride to the Great Lakes from Europe in the 1980s have
clogged water intake pipes, requiring expensive repairs, and are blamed for
a Lake Huron salmon collapse and botulism that killed thousands of shore
birds. Other invaders that arrived in ballast tanks include Asian clams in
San Francisco Bay, Japanese shore crabs along the Atlantic coast and spotted
jellyfish in the Gulf of Mexico.

“Once fully
implemented, this ballast water discharge standard will significantly reduce
the risk of an introduction of aquatic nuisance species into the Great
Lakes,” said Rear Adm. Michael Parks, commander of the Coast Guard’s
Cleveland district.

Under existing
rules, shippers must exchange ballast at sea or flush the tanks with salt
water if empty. But the Coast Guard acknowledged some organisms could
survive in puddles of water and mud. For the first time, the new policy
requires onboard treatment of ballast water to kill as many fish, mussels
and even tiny microbes as possible.

“It’s a major
milestone and a starting point, but it’s not nearly as strong as it should
be,” said Jennifer Nalbone of Great Lakes United, a U.S.-Canadian advocacy
group.

The rule limits
numbers of living organisms in particular volumes of water. Ships would have
to install equipment to meet standards developed by the International
Maritime Organization, an arm of the United Nations. Environmental groups
contend the limits should be 100 or even 1,000 times tougher, but industry
groups say no existing technology can do that.

A tentative
version of the Coast Guard rule issued in 2009 called for starting with the
international standard, then making it 1,000 times stronger by 2016. But the
final regulation drops the second level in favor of more research.

The Coast Guard
said it made the change after an Environmental Protection Agency study
questioned the reliability of more stringent standards. EPA has proposed a
separate ship discharge policy based on the international limits.

In a written
statement, the Coast Guard said it “fully intends to issue a later rule that
will establish a more stringent phase-two discharge standard.”

Thom Cmar, an
attorney with the Natural Resources Defense Council, said the delay was a
step backward.

“For them to say
they’ll get back in a couple of years with an analysis of whether a stronger
standard is achievable is cold comfort after it’s taken so long to finish
this round of rulemaking,” he said.

Cmar also
criticized a decision to exempt ships that remain within the Great Lakes
from the ballast standards. Environmentalists contend those ships carry
invasive species around the lakes even if they weren’t responsible for
bringing them to the U.S. The Coast Guard said research is needed into
whether existing ballast technology would work on vessels that never travel
the oceans.

Shipping
interests were unhappy the Coast Guard dropped an earlier provision
exempting vessels fitted with ballast treatment systems from having to
modify them if standards are toughened in the future.

But completion
of the rule is mostly good news for ship owners who have delayed installing
equipment until they knew what would be required, said Steve Fisher,
executive director of the American Great Lakes Ports Association.

“This will
create a huge international demand for ballast water treatment equipment,”
Fisher said. “Companies that manufacture it will be able to justify spending
the money for mass production. The most viable and cost-effective systems
will float to the top.”